The invention pertains to digital data processing and, more particularly, methods and systems for synchronizing processes executing on a digital data processing system.
Early computer programs were typically written for “stand-alone” operation. Since most computers had limited processor and memory resources, they could execute only a single sequence of instructions at a time. Although databases and other resources were sometimes shared among multiple programs, they were typically executed at different times and, often, by different users. Thus, for example, personnel in the bookkeeping department might use one program to enter records into a computerized accounting log, while the personnel in the accounting department would use another program to print that log. As early user interfaces were relatively unrefined, it would not be unusual for those programs to refer to the accounting log and its data in very different ways.
As processor resources increased and interface techniques improved, programmers began writing software packages that operated simultaneously with one another and that displayed and printed shared data on more uniform bases. Developers of these early integrated packages attempted to insure that data files written by one program in a package could be read by another program in that package. Thus, for example, most packages permitted a table generated by a spreadsheet application to be read into the corresponding word processing application. In addition, many packages capitalized on object embedding technologies to “dynamically” link the data files generated by one application program into those of another. For example, a table generated by a spreadsheet application could be embedded in a word processing document so that changes made by the former were automatically included in the later.
A problem with prior art integrated packages is that they are not sufficiently integrated. For example, although data generated by one application can be dynamically linked into another, both applications typically cannot modify that data. Instead, current technologies restrict modification to the “source” application, i.e., the application that generated the data in the first instance. In addition, only the source application can format an embedded item. Thus, for example, the arrangement of a table that is dynamically embedded into a word processing document is restricted to the spreadsheet application that created that table.
An object of this invention is to provide improved digital data processing methodologies and, more particularly, improved methods for synchronizing processes executing on a digital data processing system.
A related object of the invention is to provide such methods as are suited for processes that share common data or that maintain corresponding data sets.
Another object upset of the invention use to permit such synchronization regardless of whether the processes are executing on the same computer or across networked computers.
Still another object of the invention is to provide methodologies that can be implemented at minimum cost for use with a broad range of applications program and across a wide spectrum of hardware and software platforms.